I'm going to be shooting a Half Iron man for my family of 4 people excluding myself and my main question is what lens should I use, I don't want to spend anything over 1500. The race is not until Fathers Day weekend but I'd really like to get the lens and start shooting with it to get used to it and such. Anyway, I was looking at a Sigma APO 50-500mm f4-6.3 and I was wondering if that would be good enough of if I should go for something bigger. Like a super tele-photo. Any recommendations are welcome even if it's above my limit, I can probably rent it. Thanks, Corbin.